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Organic color-tunable phosphorescent materials depend upon multiple emission centers to achieve color-tunable phosphorescence with changes in excitation wavelength, temperature, time, and other external factors. Organic color-tunable phosphorescent materials are becoming increasingly popular due to their potential applications in anticounterfeiting, encryption and sensing. This brief review focuses on the formation of multiple emission centers in organic color-tunable phosphorescent materials and how to ensure that these multiple emission centers can simultaneously emit. In the future, materials with a large color tunable ranges, increased efficiency, and relatively long lives will be developed.

Macroscopic assembly of graphene sheets has renovated the preparation of neat carbonaceous fibers with integrating high performance and superior functionalities, beyond the pyrolysis of conventional polymeric precursors. To date, graphene microfibers by the liquid crystalline wet-spinning method have been established. However, how to reliably prepare continuous neat graphene nanofibers remains unknown. Here, we present the electrospinning of neat graphene nanofibers enabled by modulating colossally extensional flow state of graphene oxide liquid crystals. We use polymer with mega molecular weight as transient additives to realize the colossal extensional flow and electrospinning. The neat graphene nanofibers feature high electronic quality and crystallinity and exhibit high electrical conductivity of 2.02 × 106 S/m that is to be comparable with single crystal graphite whisker. The electrospinning of graphene nanofibers was extended to prepare large-area fabric with high flexibility and superior specific electrical/thermal conductivities. The electrospinning of graphene nanofibers opens the door to nanofibers of rich two-dimensional sheets and the neat graphene nanofibers may grow to be a new species after conventional carbonaceous nanofibers and whiskers in broad functional applications. Electrospinning of neat graphene nanofibers is realized by achieving the colossal extension flow of GO dispersion with the assistance of mega polymer. Neat graphene nanofibers and fabrics show good continuity, high crystallinity, excellent conductivity and thermal conductivity, having great potentials in extensive applications.

Luminescent materials show great potential in various applications. Traditional aggregation-induced emission (AIE) luminogens are mostly produced by complex organic synthesis and have poor hydrophilicity and biocompatibility, which limit their practical applications. Therefore, it is of great significance to develop fluorescent materials with good hydrophilicity and biocompatibility, and biomacromolecules with these properties have attracted our attention. Partial biomacromolecules can generate unique new fluorophores during the gelation process to obtain hydrogels with good fluorescence properties. In addition, biomacromolecules can be modified with fluorescent groups to obtain fluorescent materials with excellent performance, thus improving the hydrophilicity and biocompatibility of fluorophore. In particular, grafting aggregation-caused quenching (ACQ) luminogens onto biomacromolecules can even effectively inhibit the aggregation and self-quenching of luminogens. It is well known that aromatic biological macromolecules such as green fluorescent protein have intrinsic fluorescence. Intrinsic fluorescence is also observed in nonaromatic biological macromolecules without traditional chromophores such as chitosan, cellulose and sodium alginate. The luminescence of nonaromatic biomacromolecule can be rationalized by the clustering-triggered emission (CTE) mechanism, namely, clustering of nonconventional chromophores and subsequent electron overlap and conformation rigidification are accountable for the emssion. In this review, fluorescence gels obtained from biomacromolecules, biomacromolecules modified with fluorophores, and the intrinsic luminescence of biomacromolecular luminogens are assessed. This review will help to develop low-cost, biocompatible luminescent materials and has great significance for comprehending the luminescence of nonconventional luminophores and expanding the application of luminescent compounds.

The key to develop high specific energy rechargeable batteries is development of new electrode materials. The existing electrode materials still have many problems: the shuttle effect and poor conductivity of the sulfur cathode, the inevitable volume expansion of the silicon anode and the lithium dendrite of the lithium metal anode that cause short circuits, etc. Nanofibers, as active electrical materials, conductive additives and electrode bodies, can play multiple roles in electrode design. More interestingly, nanofibers can be functionalized to obtain better controllable properties (i.e., electrolyte affinity, pore size distribution and surface electronic structure), thereby further enhancing electrochemical performance. In this article, the latest research progress in electrode design based on nanofibers is reviewed, including processing methods, structure, morphology and electrochemical performance. The key problems affecting the electrochemical performance of the electrode are also discussed, such as the preparation process, atomic structure, electrical conductivity, surface area and pore distribution of nanofibers, to provide reference points for nanofibers in excellent electrode design.

Seeking an optimal catalyst to accelerate conversion reaction kinetics of room-temperature sodium-sulfur (RT Na-S) batteries is crucial for improving their electrochemical performance and promoting the practical applications. Herein, theoretical calculations of interfacial interactions of catalysts and polysulfides in terms of the surface adsorption state, interfacial ions migration, and electronic concentration around the Fermi level are systematically proposed as guiding principles of catalyst selection for RT Na-S batteries. As a case, MoN catalyst is accurately selected from transition metal nitrides with different d orbital electrons, and for experiment, it is introduced into the carbon nanofibers as a dual-functioning host (MoN@CNFs). The MoN@CNFs can effectively anchor polysulfides and accelerate their conversion reaction. In addition, for the sodium anode, the MoN@CNFs can also induce uniform deposition of Na and inhibit dendrite growth, which are supported by in situ characterizations and finite element simulation technique. As a result, the as-prepared RT Na-S battery displays high reversible capacity of 990 mAh g

Smart afterglow materials in response to excitation and delay time, including crystals, polymeric films, and carbon dots, have attracted considerable attention on account of their fundamental value in photophysics and promising applications in optoelectronics. However, the fabrication of amorphous and flexible polymer films with fine control remains underexplored. Herein, new doped polymer films based on sodium alginate and aromatic carboxylates are developed, which demonstrate following advantages: (i) easy and fast fabrication through the aqueous solution process, (ii) flexible, transparent, and re-dissolvable characteristics, (iii) multi-tunable afterglow colors from blue to red and even white with fine control. Specifically, even better controllability can be achieved through co-doping and triplet-to-singlet Förster resonance energy transfer (TS-FRET). Multimode advanced anti-counterfeiting of these materials is demonstrated using their excitation- and time-dependent as well as TS-FRET-mediated afterglow colors.

Structure and properties are the main research topics related to polymers. Traditional research methods have the disadvantages of high cost and harsh detection conditions. Fluorescence imaging technology has the advantages of high sensitivity and effective visualization. The application of traditional fluorescent dyes is limited by the aggregation-caused quenching (ACQ) effect. Unlike ACQ molecules, aggregation-induced luminescence (AIE) molecules exhibit high emission in the aggregated state or solid state. This review summarizes the application of AIE molecules in the study of the structure and properties of polymers, including the visualization of structure, phase separation, self-assembly processes, the gelation process and the analysis of swelling properties, solubility parameters, molecular motion and cracks. Finally, the prospect of development by AIE molecules in the polymer field is suggested.

Multifunctional textiles based on cotton have attracted wide attentions recently. In this study, the cotton fabrics were synergistically modified by surface micro-dissolution and cationization to enrich the adsorption of negatively charged graphene oxide (GO) on it. Subsequently, the bound GO was chemically reduced to rGO by using L-Ascorbic acid to endow cotton with high UV resistance and conductivity. By XRD, FTIR and zeta potential analysis, it was concluded that the synergistic modification could alter the structure of cotton and at the same time facilitate the reactions between cotton molecules and cationic agent EPTAC. This would shield more negative charges in cotton to decrease its absolute zeta potential, enhancing the uptake of negatively charged GO on the surface of cotton significantly. In addition, SEM, FTIR and Raman spectroscopy were utilized to confirm the presence of rGO on the surface of cotton fabrics. The result from resistance measurement disclosed that the synergistic modification could significantly reduce the electrical surface resistance of cotton to 3.89 × 103 Ω/sq. Moreover, the synergistic modification could greatly improve the UV protection factor (UPF) of cotton from 24.18 to 487.91, far beyond the excellent UPF rating (50+). The high UV resistance and conductivity of this rGO coated cotton fabrics suggests that they can be used as functional textiles for various applications.

Flexible and Personalizable battery is a promising candidate for energy storage, but suffers from the weldablity and large-scale producibility of the electrode. To address the issues, we design a nickel foam catalyzed electroless deposition (NFED) derived 3D-metal-pattern embroidered electrodes. This is the first attempt to utilize this type of electrode in battery field. It is found that the current collector can be embroidered on any selected areas of any complex-shape electrodes, with high controllability and economical feasibility. As a result, the electronic conductivity of the flexible electrodes can be improved by nearly one order of magnitude, which can be easily and firmly weldded to the metal tab using the industry generic ultrasonic heating process. The embroidered electrodes could substantially promote the electrochemical performance under bending deformation, with both Li-S and Li-LiFePO4 batteries as the models. This innovation is also suitable to embroider all the VIII group elements on any electrodes with personalized shapes, which is widely attractive for the development of next generation flexible and personalizable energy storage devices.

It is a textbook knowledge that protein photoluminescence stems from the three aromatic amino acid residues of tryptophan(Trp), tyrosine (Tyr), and phenylalanine (Phe), with predominant contributions from Trp. Recently, inspired by the intrinsic emission of nonaromatic amino acids and poly(amino acids) in concentrated solutions and solids, we revisited protein light emission using bovine serum albumin (BSA) as a model. BSA is virtually nonemissive in dilute solutions (≤0.1 mg mL-1 ), but highly luminescent upon concentration or aggregation, showing unique concentration-enhanced emission and aggregation-induced emission (AIE) characteristics. Notably, apart from well-documented UV luminescence, bright blue emission is clearly observed. Furthermore, persistent room-temperature phosphorescence (p-RTP) is achieved even in the amorphous solids under ambient conditions. This visible emission can be rationalized by the clustering-triggered emission (CTE) mechanism. These findings not only provide an in-depth understanding of the emissive properties of proteins, but also hold strong implications for further elucidating the basis of tissue autofluorescence.

Nanofiber membranes from natural alginate are ideal adsorption materials for removing cationic dyes in solution, yet the regulations to their adsorption and desorption properties are of great challenges. In this research, gelatin/calcium alginate (GA) composite nanofiber membranes were successfully prepared via electrospinning to resolve these issues. The structural changes of composite membranes induced by the gelatin addition were confirmed by SEM, FT-IR and BET analysis. The enhanced mechanical strength of GA membranes disclosed the strong interactions between gelatin and alginate chains. Taking methylene blue (MB) as the model cationic dye, it was found the resultant composites could slow down the adsorption rate and obviously improve the adsorption evenness without apparent influences on its adsorption capacity. Moreover, the gelatin modification would generate better reusability for the composite membranes during a serial of adsorption and desorption cycles for strong electrostatic repulsions induced by protonated amino groups in gelatin chains. This effective composite strategy would pave the way for the development of natural alginate to the next generation high-performance adsorbent for cationic dyes.

Herein, the three kinds of water-insoluble alginate-based nanofiber membranes were prepared by electrospinning and followed with crosslinking by calcium chloride (CaCl2), glutaraldehyde vapor (GA), and trifluoroacetic acid (TFA) crosslinking, respectively. All the sodium alginate(SA) nanofiber membranes present excellent integrated adsorption performance toward methylene blue (MB). Among these, CaCl2 crosslinked SA membranes exhibit the maximum actual adsorption capacity of 2230 mg/g and shortest adsorption equilibrium time of 50 min to date. On the basis of the selective adsorption of SA, the nanofiber membranes can separate MB/ methyl orange (MO) mixture solution and maintain high separation efficiency even after five cycles. In addition, respective applicable condition for differentially crosslinked SA nanofiber membranes was evaluated. The TFA crosslinked membranes have the least reduction in the adsorption capacity in acidic environment and GA crosslinked membranes adsorb better in alkaline environment. For seawater environment, GA crosslinked membranes show obvious adsorption performance than other crosslinked membranes.

There is a growing demand for flexible and stretchable strain/pressure sensors for different applications. However, existing conductors usually cannot meet all the requirements for use in next-generation wearable sensors. In this work, we demonstrate a new class of nature-inspired ionic conductors based on supramolecular sodium alginate (SA) nanofibrillar double network (DN) hydrogels with complex shapes by injection. Owing to their dermis-mimicking structures, these hydrogels exhibit unique features, such as high transparency (99.6%), high tension/compression strength (0.750 MPa/4 MPa), high stretchability (3120%), high toughness (4.77 MJ m−3) and superior elasticity (100%) at high strain (1000%). In particular, the use of salts (e.g., NaCl) as triggers in supramolecular assembly combining SA makes the hydrogels ideal ionic conductors. The ionic conductors were demonstrated as strain sensors with high sensitivity to an extremely broad strain window (0.3–1800%) and a low applied voltage (down to 0.04 V), as well as with high pressure sensitivity (1.45 kPa−1). These hydrogel-based ionic sensors may find applications in sports monitoring, human/machine interfaces and soft robotics.

A facile way to simultaneously induce the formation and enhance the stability of graphene oxide liquid crystals (GO LCs) is reported. Sodium alginate (SA) with both inductive effect and stabilization effect was added into GO suspensions to prepare LCs at low concentration that could survive harsh conditions. Most importantly, different concentration zones of SA brought significantly different LCs degree and stability, which possessed distinct charge properties, rheological behaviors and chain morphology. Adding 0.5% SA located in entangled semi-dilute regime could induce the isotropic-nematic transition of GO at low concentration (

It is challenging to fabricate a starch derivative with a plasticizing effect and good dispersion in a poly(lactic acid) matrix to achieve desirable performance. In this study, self-suspended starch fluids composed of modified granules as the core and polyethylene glycol-substituted tertiary amines as the shell were first fabricated via a combined carboxymethylation and acylation reaction. The as-prepared starch fluids exhibited liquid-like behavior and had semiconductor electric conductivity (4.91 × 10−5 S/cm) at room temperature without a solvent. The modulus of starch fluids was clearly reduced under the heating process and exhibited its initial flow properties upon cooling, displaying thermo-reversible behavior. The resultant fluids were then incorporated into a poly(lactic acid) matrix to produce fully biodegradable composites with desirable performance. At a loading level of 10 wt%, starch fluids exhibited simultaneous enhancements in elongation at break (increase of 164.7%) and thermal conductivity (increase of 119%) of PLA composites compared to pure PLA, attributable to the good dispersion and heat-transfer properties of starch fluids. In addition, PLA composites with 10 wt% loading of starch fluids demonstrated excellent antistatic performance (3.08 × 10−4 S/cm), suggesting that polar groups of the PLA structure and PEG groups of starch fluids contributed synergistically to the electrical conductivities of composites. These results indicate that starch fluids are promising antistatic agents and plasticizers for potential applications in biodegradable materials.

The phase behavior of biomolecules containing persistent molecular entities is generally limited due to their characteristic size that exceeds the intermolecular force field. Consequently, favorable properties normally associated with the liquid phase of a substance, such as fluidity or processability, are not relevant for the processing of biomolecules, thus hindering the optimal processing of biomolecules. The implied problem that arises is how to convert folded biomolecules to display a richer phase behavior. To alleviate this dilemma, a generic approach to liquefied polysaccharides-based polymers is proposed, resulting in a polysaccharide fluid with a tunable condensed state structure (solid-gel-liquid). Polysaccharide biobased fluids materials transcend the limits of the physical state of the biobased material itself and can even create completely new properties (different processing methods as well as functions) in a variety of polymeric structures. Considering the solvent incompatible high and low-temperature applications, this method will have a great influence on the design of nanostructures of biomolecular derivatives and is expected to transform biomass materials such as polysaccharide biopolymers from traditional use to resource use, ultimately leading to the efficient use of biomass materials and their sustainability.

In this paper, a reactive amphiphilic alginate was prepared by an Ugi reaction using 4,4′-diaminostilbene-2,2′-disulfonic acid and its structure was analyzed by FT-IR and 1H NMR measurement. Subsequently, it was utilized as emulsifier to prepare polyurethane acrylate (PUA) emulsion and the colloidal properties including zeta potential, droplet size distribution and stability were evaluated. The results showed that the PUA emulsion by this modified alginate had better colloidal stability than that by original one. Finally, stable PUA emulsion was used for surface treatment of cotton fabrics in a UV curing process to improve their anti-wrinkle performance. By measuring the wrinkle recovery angle, it was found the anti-wrinkle properties of cotton fabrics were significantly improved with the increase in the amount of modified alginate. In addition, this anti-wrinkle finishing method was found to have many advantages such as low temperature, low yellowing as well as high washing resistance.

In this paper, solvent-free microcrystalline cellulose fluids (MCCFs) with liquid-like behavior were synthesized for the first time through surface grafted polyethylene glycol-substituted tertiary amines into microcrystalline cellulose (MCC) followed by fabricating MCCFs based polylactic acid (PLA) fabric (PLA/MCCFs) via electrospinning method. Owing to low viscosity of MCCFs at room temperature, the addition of MCCFs not only hardly affected the viscosity of electrospinning solution, but also improved the thermal stability of as-prepared PLA fibers. Interestingly, it was amazingly found that surface micropore morphology of PLA fabric diminished, and even disappeared with the content of MCCFs increasing during solvent evaporation process, which may be ascribed to the rapid migration of MCCFs into micropore before solidification. More importantly, the tensile strengths of PLA/MCCFs fabric with 10 wt% content of MCCFs achieved as high as 13.68 MPa, which was 3.18 times as much as that of 4.3 MPa for pure PLA fabric meanwhile the elongation at break of PLA/MCCFs fabrics increased from 13.19% for pure PLA fabric to 48.84% for PLA/MCCFs fabric with 15 wt% content of MCCFs. Beyond above mentioned, the water contact angle for pure PLA fabric was 127° (hydrophobicity), whereas other samples were close to 0° with addition of MCCFs, displaying the super-hydrophilicity. It was possibly inferred that MCCFs quickly migrated towards to the surface of fibers rather than staying inside of the fibers during the electrospinning process, leading to positive effect on the hydrophilicity of the PLA fibers. Finally, it is anticipated that this strategy for fabricating PLA fiber using this novel MCCFs as filler will pave the way for developing high performance PLA composites with desirable properties in the future.

Superhydrophobic material involves the fabrication of appropriate roughness and low surface energy. Studies concerning enhancing the attachment between substrates and low surface energy material have been reported. Hence, it might also be feasible to make low surface energy material as an interface binder to enhance the attachment. In our work, the simple dip-coating method was used to fabricate polybenzoxazine (PBZ)/SiO2-coating cotton (PBZSC) fabric for rapid oil–water separation. The surface morphology and wettability of the PBZSC fabric as well as the properties of the separation were explored using various methods. These results demonstrated that PBZSC fabric not only had excellent thermal properties, but also maintained excellent superhydrophobicity (WCA > 150°) under various harsh conditions which was mainly attributed to higher surface roughness contributed by SiO2 and lower surface energy, heat resistance as well as acid and alkali resistance from PBZ resin, respectively. More importantly, the separation conducted by the PBZSC fabric not only showed great recycle property, but also separated a series of oil and water mixtures with up to 96% separation efficiency. Therefore, it is anticipated that this low-cost PBZSC fabric will be readily and widely utilized in designing multifunctional membrane for large-area oil-spill cleanup without using fluoropolymers or silicones.

Nonconventional biomacromolecular luminogens have attracted extensive interest due to their fundamental importance and potential applications in diverse areas. To explore novel luminogens and, moreover, to gain deeper insights into their emission mechanism, we study the emission behaviors of sodium alginate (SA), a natural anionic polysaccharide composed of mannuronic (M) and guluronic acids (G). We find that the luminescence from aqueous SA solutions exhibits distinct concentration enhanced emission and aggregation-induced emission (AIE) characteristics. Meanwhile, the ratio of M/G also matters. Rheological measurements reveal the distinct regimes of the solutions, which are consistent with the observed emission, indicative of strong association between the chain entanglement and emission. Moreover, we observe persistent room temperature phosphorescence (RTP) in the amorphous SA solids, which is a rare case even in pure organic aromatic luminogens. Such unique emission can be remarkably enhanced via coordination with Ca

From the industrial viewpoint, it would be desirable to use neutral aqueous solution when applying chitosan coatings for textile treatment. However, in most cases, chitosan only dissolves in acid solvents. In this work, a self-suspended chitosan derivative with liquid-like behavior was prepared by decorating chitosan with a quaternary ammonium salt followed by ion exchange with nonylphenol polyoxyethylene ether sodium sulfate (NPES). The chitosan derivative with higher NPES content dissolved in neutral aqueous solution, and even exhibited liquid-like viscous behavior without water at room temperature. The morphology, structure, composition, and rheological behavior of the chitosan derivative were systematically characterized using various methods. It was found that incorporation of NPES into the chitosan structure could greatly enhance its dispersion, while the modulus and viscosity of the derivative gradually decreased with increasing temperature. Moreover, the novel chitosan derivative not only directly coated cotton fabric via hydrogen-bonding interaction without removing water but also improved the long-term wettability and moisture retention because of the dual-layer ion structure of the chitosan derivative. The results showed that cotton fabrics coated with such chitosan derivatives could be developed as wound dressing materials in future work.

In this work, a novel type of functionalized magnetic graphene oxide (MGO) nano-sheets which have the ability to capture His-tagged CotA laccase was synthesized. Nα,Nα-Bis(carboxymethyl)- l -lysine hydrate (NTA-NH2) was attached on MGO then chelated with Ni2+ and Cu2+ separately. The Cu2+-chelated MGO (MGO-NTA-Cu2+) exhibited the highest adsorption capacity of 177 mg/g-support when compared with both MGO and Ni2+-chelated MGO (MGO-NTA-Ni2+) which exhibited an adsorption capacity of 49.9 and 145 mg/g-support, respectively. CotA laccase immobilized on MGO-NTA-Cu2+ nano-sheets showed the highest activity recovery when compared with that immobilized on MGO-NTA-Ni2+ nano-sheets. The catalytic properties of MGO-NTA-Cu-CotA laccase were significantly improved in comparison with those of the free laccase. MGO-NTA-Cu-CotA laccase showed efficient decolorization for Congo Red (CR), and the decolorization rate reached 100% after 5 h reaction at 60 °C and pH 8. Furthermore, MGO-NTA-Cu-CotA laccase retained 89.4% of its initial activity after 10 consecutive cycles. Together these results indicated that the Cu2+ chelated MGO nano-sheets are promising support for efficient CotA laccase immobilization for environmental and industrial applications under high temperature and alkaline condition.

The preparation of ultralight, superelastic and multifunctional graphene aerogels still remains a challenge. Herein we develop a silane-crosslinked and modified graphene aerogel (SGA) using a novel and simple method of chemical vapor deposition of methyltriethoxysilane into graphene oxide aerogels. The SGA is mechanically robust and shows fantastic properties satisfying multiple applications. Firstly, the SGA exhibits hitherto the highest compression recoverability (99.5%), as well as a high energy loss coefficient and cycle stability. Secondly, the compressible and ultralight (minimum density of 0.35 mg cm−3) SGA could serve as a fast and recyclable superadsorbent being able to adsorb various organic liquids with ultrahigh capacity (>1000 g g−1), which is almost the highest value among known adsorbents. Moreover, the electrical resistance of SGA is highly sensitive to compressive strain and applied pressure due to the enhanced connection between adjacent graphene sheets, which makes the SGA a great pressure sensor with high sensitivity (−67.1 kPa−1) and a low detection limit (

Functionalized magnesium hydroxide fluids (MHFs) with both grafting reactive acrylate groups and organic long chain ion are successfully fabricated and then incorporated in poly(ethylene glycol) diacrylate (PEGDA) to produce flexible MHFs/PPEGDA coated hybrid cotton fabric via UV photo-polymerization. The morphology, composition, transparency, rheological behavior, mechanical and flame retardant properties of MHFs/PPEGDA coating are systematically characterized by various techniques. It is found that tensile strength and young’s modulus of MHFs/PPEGDA/cotton composite are as high as 46 and 556 MPa at MHFs loading amount of 40 wt%, respectively, an enhancement of 58.6 and 66.4% in comparison with PPEGDA/cotton composite. What’s more, the addition of MHFs not only reduces the surface energy of PEGDA to improve its film-forming property during polymerization process, but also maintains high transparency over 90%. Besides the above mentioned advantages, MHFs/PPEGDA coating as thermal induced shape memory material could be fixed their shape at − 4 °C and rapidly recover their original shape at 60 °C, which is related to the melting transition temperature of MHFs. More importantly, with the synergistic effect of magnesium hydroxide and surface grafted organic long chain ion molecules, the flame retardant property of MHFs/PPEGDA/cotton is also significantly improved. These functionalized organic/inorganic fluids provide a simple approach to fabricate high performance cellulose fabrics with tunable properties in the textile industry.

Solid electrolyte has good mechanical strength and can effectively inhibit the growth of lithium dendrite, so it has a good application prospect in lithium batteries , especially solid polymer electrolyte (SPE), such as PEO. Due to the stability of lithium metal and the excellent dissociation ability of lithium salts, PEO and its derivatives are the mainstream SPE materials. PEO performs best at high temperatures. However, the flammability and fluidity of PEO at high temperatures may pose safety concerns. In this study, sodium alginate (SA) was introduced into PEO to improve the mechanical properties of SPE and the safety of the battery through the nanofiber membrane structure. The PEO/SA composite solid electrolyte has excellent flame retardance (LOI = 28.6), good thermal stability (>120 °C) and wide electrochemical window (>4.6 V). This will help further research on lithium batteries with high energy density and voltage.

Alginate is a kind of marine-derived plant polysaccharide with useful properties including inherent flame-retardancy and biocompatibility, yet poor flowability and low processing efficiency induced by high viscosity impede its further industrial applications. In this study, PEG-substituted tertiary amines were adapted to functionalize alginate with different molecular weight via acid-base reaction to improve the flowability. Based on alginate with low molecular weight, alginate fluids exhibited excellent flowability at room temperature in the absence of solvent. For alginate with high molecular weight, gelatinous precipitated phase exhibited significant shear-thinning properties and higher solid content despite lack of solvent-free flowability, which was applied to wet-spinning. The alginate fibers exhibited increased tensile strength by 104% and elongation at break by 132% compared with conventional alginate fibers, and the spinning efficiency was significantly improved. The proposed strategy is expected to extend to highly efficient processing of other polysaccharides to obtain high-performance biomedical materials.

A convenient and green approach was utilized to prepare the suspended carbon black fluids (SCBF) using carboxylic CB nanoparticles with diameters of 15nm as the core and poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) (PEO-b-PPO-b-PEO) as surface modifier via hydrogen bonding interaction. It was found that when the total polymer content (strongly adsorbed layer and weakly adsorbed or free layer) was greater than 60wt%, the SCBF exhibited liquid-like behavior without solvent. More interestingly, the flow mechanism mainly related to surface polymer content, which greatly differed from ionically or covalently nanofluids systems. Besides, the thermal, dispersibility, electrical conductivity properties and rheological behaviors, as well as microstructure of SCBF were systematically investigated using various methods. Moreover, the SCBF as fillers were used to prepare SCBF/Poly(vinyl alcohol) (PVA) composites for producing the simultaneous reinforcement and plasticization effect due to the unique fluidity of SCBF and interfacial interactions between the PVA molecules and SCBF via hydrogen bondings. Keywords: Nanofluids, Reinforcement, hydrogen bonds, Nanocomposites

Self-reinforcement gel-like halloysite nanotube (g-HNT) hybrids with various viscoelastic behaviors were fabricated by firstly treating with various concentrations of sodium hydroxide (NaOH) solution and then grafting tertiary amine and ion-exchange reacting with sulfonate anions. The morphology, composition, thermal stability and rheological behavior of the g-HNT hybrids were systematically characterized and analyzed using various methods. It is found that the viscoelasticity of g-HNT hybrids can be easily regulated by using different NaOH solution-treated HNTs as inorganic core and temperatures. In addition, the g-HNT hybrids treated with medium concentration of NaOH (0.06 mol L−1) have the lowest viscosity and highest level of dispersion compared with those treated with other concentrations of NaOH solution. Due to the amphiphilic nature of g-HNT hybrids and their lower viscosity than HNT powder, as novel hybrid fillers, they were utilized to prepare polystyrene composites by direct melt blending for achieving simultaneous reinforcement and plasticization effects. Besides the above mentioned advantages, the thermal conductivity of polystyrene composites is also surprisingly improved by reducing the interfacial mismatch between the filler and polymer matrix. The solvent-free and self-reinforcement hybrids provide a convenient and green path for fabricating high-performance polymer composites. © 2017 Society of Chemical Industry

Filling can cause polymer melt to undergo a so-called fluid-to-solid transition usually assigned to filler networking effect and heterogeneously retarded polymer dynamics while theories developed nowadays could not account for the several important aspects involving in the reinforcement and dissipation of the composites including the influence of molecular weight of the matrix. Herein linear dynamic rheological behaviors of carbon black filled polystyrene (PS) was investigated, disclosing significantly influences of weight-averaged molecular weight ( M w ) of PS on the reinforcement and dissipation in and beyond the hydrodynamics regime. Attempts to create rheological master curves in hydrodynamics regime, taking account for both dynamics retardation in bulk polymer phase and strain amplification effect induced by filler, disclose time-concentration superpositions. The viscoelastic contributions from the dynamically retarded polymer phase and the viscoelastic “filler phase” are thus evaluated.

Electrospinning of pure alginate or derivatives has always been a pursuing goal in biological fields in recent years owing to its fascinating biological characteristics and biomimetic structures. Yet it is still a severe challenge in view of its insufficient entanglements and strong electrostatic repulsions. Herein, alginate dialdehyde (ADA) with improved and adjustable chain flexibility was prepared via periodate-oxidation. Chain flexibility, concentration, ethanol and crosslinkers played key roles in electrospinning proved by persistence length (lp), the number of entanglement points (ne) and fiber morphology. Finally, insoluble ADA corsslinked nanofiber membranes were obtained, which exhibited excellent mechanical properties and adjustable degradability. Specially, biocompatibility assays confirmed that the preparing membranes were noncytotoxic, and could promote cell attachment and proliferation. Therefore, under the guidance of the relationship between chain flexibility and electrospinnability, pure alginate-based nanofiber membranes are expected to become promising scaffolds for biomedical applications, particularly for wound healing which demanding appropriate degradation.

Halloysite nanotubes (HNTs), novel 1D natural materials with a unique tubular nanostructure, large aspect ratio, biocompatibility, and high mechanical strength, are promising nanofillers to improve the properties of polymers. In this review, we summarize the recent progress toward the development of polysaccharide-HNTs composites, paying attention to the main existence forms and wastewater treatment application particularly. The purification of HNTs and fabrication of the composites are discussed first. Polysaccharides, such as alginate, chitosan, starch, and cellulose, reinforced with HNTs show improved mechanical, thermal, and swelling properties. Finally, we summarize the unique characteristics of polysaccharide-HNTs composites and review the recent development of the practical applications.

High performance strain sensors have recently attracted immense interest because of their potential applications in wearable devices. However, it remains a challenge in achieving critical feature combinations (e.g., high sensitivity, high mechanical properties, and easy fabrication) for soft wearable sensors. Herein, we fabricated new ionic strain sensors based on agar/NaCl/polyacrylamide double network hydrogels. By taking the advantage of the electric neutrality of agar, we can easily combine the sensitivity and mechanical properties into same ionic hydrogel by tuning the chemical compositions of the hydrogels. Moreover, thanks to the thermoreversible sol-gel properties of agar, the pregel can be injected into various complex shapes. The ionic hydrogels exhibit high strain sensitivity and many superior mechanical properties. The ionic sensor can monitor human motions such as joint motions, slight wrist pulse and subtle muscle movements of throat. Thus, this study demonstrates that the ionic hydrogels have potential applications as high performance strain sensors.

This paper first develops a novel approach to prepare solvent-free nanonickel (Ni) nanofluids via hydrogen bonding between poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) and 3-(Trimethoxysilyl)-1-propanethiol-modified Ni powder with average diameter of 80 nm to solve the problem of nanoparticles agglomerating due to the anisotropic dipolar attraction. It is interestingly found that Ni nanofluid is solid at room temperature while it undergoes solid–liquid transition without solvent at 50.7°C. The content of Ni is up to 12.1 wt%. The average diameter of core-shell structure of Ni nanofluids is 182 nm without agglomerations. It is worth noting that incorporation of Ni powder can elevate remarkably initial decomposition temperature of block copolymer due to high dispersity of Ni powder after modification. In addition, the viscosity of Ni nanofluids is found to be less than 10 Pa · s at 100°C, which is between that of water and honey, 0.001 and 10 Pa · s, respectively, at 2...